用正交试验法筛选樟芝菌适宜发酵培养基

用正交试验法对樟芝菌 (AntrodiacamphorataZang&Su)的发酵培养基进行了研究。选取马铃薯淀粉、葡萄糖、麦芽糖、酵母膏、蛋白胨、麸皮、KH2 PO4 、MgSO4 ·7H2 O等作为试验因素 ,采用L2 7(31. 3)正交表设计五因素、三水平的正交试验 ,对所选各因素的添加量分别作了试验 ,对菌丝干重和发酵液多糖含量结果作了方差分析 ,确定了合适的发酵培养基。试验结果表明 :樟芝菌的深层发酵适宜培养基是 :马铃薯淀粉 1 .0 0 % ,葡萄糖2. 0 0 % ,酵母膏 0 . 10 % ,蛋白胨 0 . 10 % ,麸皮 1 .0 0 % (或 0. 5 0 % ) ,KH2 PO4 0 . 10 % ,MgSO4 ·7H2 O 0 . 0 5 %。     

菌核侧耳液体培养条件优化研究

运用液体深层培养法,采用不同pH值、不同碳源和氮源对菌核侧耳菌丝体生长的影响进行了探讨。结果表明:菌核侧耳菌丝体生长的培养基适宜pH值为5.0～6.5,葡萄糖、蔗糖、乳糖和纤维素是菌核侧耳菌丝体生长的适用碳源;黄豆、麦麸、酵母膏和蛋白胨等为适宜氮源;其中以黄豆浆作为氮源,蔗糖作为碳源,初始pH5.0为最佳条件组合。     

一株海洋真菌菌株M-01产抑菌物质发酵条件研究

对从海泥中分离到的1株海洋真菌菌株M-401产抑菌物质的发酵条件及所产抑菌物质的热稳定性、pH稳定性进行了初步的研究。结果表明,菌株M-401适宜发酵培养基组成为马铃薯40%,蛋白胨0.6%,酵母膏0.2%,葡萄糖1%,海水100%;培养基初始pH值为6.0~7.0;发酵温度24℃,发酵时间48~72 h;抑菌物质80℃处理1 h,残留活性60%,pH稳定范围在4~8之间。     

红酵母NZ-01发酵条件的优化

以红酵母菌株NZ-01为试验菌株,研究其发酵工艺与中试生产。采用摇瓶发酵优化的方式,研究培养基组分与发酵工艺条件对该菌发酵的影响,并进行中试放大生产。结果显示,该菌最适生长培养基组分为葡萄糖10g/L,蔗糖10g/L,酵母膏10g/L,牛肉膏2.5g/L;色素合成最适培养基组分为葡萄糖15g/L,蔗糖10g/L,酵母膏2.5g/L,牛肉膏5g/L。最适生长起始pH值为6.0,最适接种量为8%,生长周期为44h;最适色素合成起始pH值为7.0,最适色素合成接种量为8%,色素合成周期为48h。发酵优化后的色素产量3.88μg/mL较优化前1.71μg/mL提高了127%。中试产量达3.05μg/mL。红酵母菌NZ-01优化后的发酵条件可以应用于中试生产虾青素,有规模化生产应用潜力。     

固态法生产益生素中二级液体菌种培养基配方筛选

利用正交试验 ,对固体法生产益生素中菌株NYS 2的二级液体菌种的培养基配方进行筛选 ,确定了一组最佳组合 :蛋白胨 1.0 % ,葡萄糖 1.0 % ,酵母膏 0 .5 % ,牛肉膏 1.0 % ,KH2 PO40 .0 6 % ,NaCl 0 .3% ,pH 7.2～7.4。     

玫瑰黄链霉菌NKZ-259发酵培养基的优化

玫瑰黄链霉菌NKZ-259是一株生防菌株,其次级代谢能产生植物生长调节类物质吲哚乙酸(IAA)。为了进一步提高菌株代谢产生IAA的含量,本试验对该菌株的发酵培养基进行了优化。利用单因子试验确定发酵培养基中最适的6种营养成分为葡萄糖、可溶性淀粉、蛋白胨、硝酸钾、磷酸氢二钾和L-色氨酸;通过Plackett-Burman设计筛选出影响菌株发酵产生IAA的主要因素为L-色氨酸、葡萄糖和磷酸氢二钾;采用中心组合试验(CCD)及响应面法分析各因素的交互作用。最终确定菌株代谢产生IAA的最优发酵培养基为:L-色氨酸2.24 g/L,葡萄糖20.7 g/L,磷酸氢二钾0.5 g/L,可溶性淀粉10 g/L,蛋白胨3 g/L,硝酸钾4.5g/L;使用优化后的发酵培养基菌株代谢产生IAA的含量为45.377 4μg/mL,比原始发酵培养基IAA的含量提高了3倍。     

Optimization of fermentation medium for Cordyceps militaris high producing strain

在单因素试验初步确定高产蛹虫草菌株发酵培养基的基础上,以蛹虫草菌丝体中腺苷含量为指标,进行11因素2水平Plackett - Burman试验设计试验,结合多元一次回归模型和F检验方法,筛选出发酵培养基中影响显著的组分酵母浸粉、蔗糖和维生素B1,采用旋转中心组合设计方法对这三个组分进行进一步优化,结合多元二次回归模型和响应面分析,获得高产蛹虫草菌株的最佳培养基(g/L):蔗糖18.85、蛋白胨10、酵母浸粉18.97、KH2 PO4 3、MgSO4 3、维生素B10.235、ZnCl2 0.011、(NH4)2SO4 10.验证试验结果表明蛹虫草腺苷得率较单因素优化获得的发酵培养基提高了26.91％.     

一株产酸蜡样芽孢菌的筛选鉴定及发酵条件优化

从牛粪中分离得到一株产酸芽孢菌GF1,经鉴定为蜡样芽孢杆菌,该菌株发酵最低pH值可达到4.25,发酵最终芽孢率可达到90%以上,对该菌株液体发酵培养发现GF1具有良好的生长性能,通过优化培养条件和培养基中的C源、N源,最终确定GF1发酵条件为:发酵液初始pH值7.5,摇床转速220 r/min,培养温度35℃,培养时间48 h,配方为:酵母膏0.5%,蛋白胨0.6%,葡萄糖1.0%,K2HPO4 0.5%,MgSO4 0.02%,MnSO40.08%.     

Bacillus subtilis BE-91生长及其胞外表达β-甘露聚糖酶的发酵条件优化

【目的】优化枯草芽孢杆菌(Bacillus subtilis) BE-91生长及其胞外表达β-甘露聚糖酶的发酵条件。【方法】对影响菌株生长和发酵的主要因素(C源、N源、起始pH、温度等)进行单因素试验后,采用正交试验法研究B. subtilis BE-91生长培养条件和摇瓶发酵条件的优化组合。【结果】优化生长条件为：0.3%牛肉膏、0.2%酵母膏、0.1%葡萄糖、0.4%魔芋精粉、0.5% NaCl,初始pH 6.0、培养温度35 °C;胞外表达β-甘露聚糖酶活力的摇瓶发酵条件优化组合为：0.7%魔芋精粉、0.4%大豆蛋白胨、0.1% (NH4)2SO4、0.5% NaCl,发酵温度35 °C和起始pH 6.0;优化条件下发酵10 h,β-甘露聚糖酶活力最高达432.4 IU/mL,比国内外已有相关菌株报道的发酵时间缩短了14?86 h,最高酶活力提高了5倍以上。【结论】B. subtilis BE-91生长与发酵周期短、胞外表达β-甘露聚糖酶的活力高,是酶制剂产业具有重大开发价值的菌种资源。     

常压室温等离子体快速诱变产油酵母的条件及其突变株的特性

采用新型常压室温等离子体射流诱变产油酵母,结合快速突变产油酵母操作条件及基于96孔板的高通量筛选手段,获得了一系列增殖速度和产油量发生变化的突变株。在等离子体对菌株致死率为99％的条件下获得的以突变株增殖速度为指标的正突变率达到27.2％。用含酵母粉 (10 g/L)、蛋白胨 (10 g/L) 及葡萄糖 (20 g/L) 的酵母膏胨葡萄糖培养基进行发酵实验表明,筛选得到的高产突变体产油量从对照株的1.87％ (W/W) 增加到4.07％ (W/W)。     

芳香杯伞生物学特性及驯化栽培

以采自于河北省平泉市的一株野生食用菌Clitocybe fragrans的菌丝体为材料,对其营养及环境特性进行研究。检测了不同碳源、氮源、C/N、无机盐在固体培养条件下对芳香杯伞菌丝生长的影响,单因素及正交试验结果表明,实验范围内,芳香杯伞最适碳源为蔗糖、最适氮源为酵母浸粉、最适C/N为40:1、最适无机盐为硫酸镁。正交试验筛选适宜培养基配方为：蔗糖17.3 g,酵母浸粉1.8 g,磷酸二氢钾3 g,无水硫酸镁1.5 g,琼脂20 g,水1 L。对菌丝生长所需的温度、pH及光照条件进行研究,结果显示,适宜菌丝生长的温度范围为19–25℃,pH值范围为5–5.5,光照条件为黑暗。对获得的菌种进行了驯化栽培研究,结果表明,适宜的母种扩繁培养基为：粪草培养料100 g (煮汁),马铃薯200 g (煮汁),葡萄糖20 g,磷酸二氢钾3 g,蛋白胨3 g,无水硫酸镁1.5 g,琼脂20 g,水1 L;原种培养基为：高粱粒98%,葡萄糖1%,石膏1%;栽培培养基质为：粪草培养料98%,石膏1%,葡萄糖1%,含水量55%。栽培袋接菌后35–40 d满袋,8–10 d后现原基,7–8 d原基分化成子...     

Nutritional requirements of mycelial growth of Cordyceps sinensis in submerged culture

AIMS: The nutritional requirements for mycelial growth of Cordyceps sinensis in semi-synthetic liquid media were investigated. The results provide a basis for further physiological study and industrial fermentation of the fungus. METHODS AND RESULTS: Nutritional requirements, including 17 carbohydrates, 16 nitrogen compounds, nine vitamins, four macro-elements, four trace-elements and eight ratios of carbon to nitrogen, were studied for their effects on the mycelial growth in submerged cultures of C. sinensis by using one-factor-at-a-time and orthogonal matrix methods. Among these variables, sucrose, peptone, folic acid, calcium, zinc and a carbon to nitrogen ratio 12 : 1 were identified as the requirements for the optimum mycelial growth. The concentrations of sucrose, peptone and yeast extract were optimized and the effects of medium composition on mycelial growth were found to be in the order sucrose > yeast extract > peptone. The optimal concentration for mycelial growth was determined as 50 g l(-1) sucrose, 10 g l(-1) peptone and 3 g l(-1) yeast extract. CONCLUSIONS: Under optimal culture conditions, over 22 g l(-1) of mycelial biomass could be obtained after 40 days in submerged cultures. SIGNIFICANCE AND IMPACT OF THE STUDY: Cordyceps sinensis, one of the most valued medicinal fungi, is shown to grow in axenic culture. This is the first report on nutritional requirements and design of a simplified semi-synthetic medium for mycelial growth of this psychrophilic species, which grows slowly below 20 degrees C. The results of this study will facilitate research on mass production of the fungus under defined culture conditions.     

Production of 3-acetyldeoxynivalenol in shake culture

In order to produce deoxynivalenol (DON), conditions for the production of 3-acetyldeoxynivalenol (Ac-DON) in shake culture were studied. A selected isolate of DON-producer,F. graminearum strain R2118, produced about 70mg/mL of Ac-DON when cultured at 25°C for 4 days in a medium consisting of 3% sucrose, 0.1% peptone, and 0.1% yeast extract. From the mass culture (10 L) of the strain, 792 mg of Ac-DON were isolated and 384 mg of DON were obtained after hydrolysis of the acetate.     

Optimization of propionic acid production in apple pomace extract with Propionibacterium freudenreichii

Abstract

Sequential optimization of propionate production using apple pomace was studied. All experiments were performed in a static flask in anaerobic conditions. Effect of apple pomace as nitrogen source against conventional N sources (yeast extract, peptone) was studied. The double increase was observed in propionic acid production while using yeast extract and peptone (0.29?±?0.01?g/g), as against the use of only apple pomace extract (APE) (0.14?±?0.01?g/g). Intensification of propionic acid fermentation was also achieved by increasing the pH control frequency of the culture medium from 24-(0.29?±?0.01?g/g) to 12-hour intervals (30?°C) (0.30?±?0.02?g/g) and by increasing the temperature of the culture from 30 to 37?°C (12-hour intervals of pH control) (0.32?±?0.01?g/g). An important factor in improving the parameters of fermentation was the addition of biotin to the medium. The 0.2?mg/L dose of biotin allowed to attain 7.66?g/L propionate with a yield of 0.38?±?0.03?g/g (12-hour intervals of pH control, 37?°C).     

Statistical optimization of culture media and conditions for production of mannan by Saccharomyces cerevisiae

In view of the increase in Saccharomyces cerevisiae mannan content, the culture medium and condition for S. cerevisiae were optimized in this study. The influence of culture medium ingredients such as carbon and nitrogen sources, inorganic ion, and enzyme activator on mannan production were evaluated using factional design. The mathematical model was established by the quadratic rotary combination design through response surface analysis. The optimized concentrations of culture medium were determined as follows: 4.98 g/100 mL, sucrose; 4.39 g/100 mL, soybean peptone; 3.10 g/100 mL, yeast extract; and 2.21 g/100 mL, glycerol. The optimized culture medium increased mannan production from 82.7 ± 3.4 mg/100 mL to 162.53 ± 3.47 mg/100 mL. The influence of original pH, inoculum size, temperature, and media volume on mannan production was evaluated and confirmed by orthogonale experimental design, with the order of effect as follows: media volume > temperature > initial pH > inoculation size. The optimized culture condition was pH, 5; inoculum size, 5 ml; temperature, 32°C; and media volume, 40 mL. The maximum mannan production increased to 258.5 ± 9.1 mg/100 mL at the optimum culture condition. It was evident that the mannan production was affected significantly by culture medium and condition optimization (p < 0.01).     

Methanogens in the human intestinal tract and oral cavity

Curvularia lunata var.aeria was grown in YPD (yeast extract, peptone, and dextrose) medium (pH 6.5) at 28°C with varying concentrations (10–40 g/L) of glucose for the production of rifamycin oxidase. Enzyme activity and glucose concentration were found to be indirectly related to the production of black intracellular pigment by the organism. Depletion of glucose level and rise of culture pH initiate the synthesis of pigment. Carboxymethylcellulose (CMC) was used as a carbon source to improve the enzyme yield, but utilization of the substrate in the reactor was much less. Compared with 10 g/L of CMC in the medium, low or high concentrations of CMC did not yield any better result. Addition of glucose in YPC (yeast extract, peptone, and CMC) medium did not increase the enzyme activity, and glucose was rapidly utilized byC. lunata, forming pellets rather than mycelia.     

Modified ferric hydroxamate spectrophotometry for assaying glycolic acid from the hydrolysis of glycolonitrile by Rhodococcus sp. CCZU10-1

We successfully modified a ferric hydroxamate spectrophotometry method for assaying glycolic acid. Comparable to the high-performance liquid chromatography (HPLC)-based method, ferric hydroxamate spectrophotometry can be used to accurately monitor the time course of glycolonitrile bioconversion. Glycolic acid was assayed simply and rapidly at room temperature (25 ～ 35°C). Optimum culture conditions were obtained using this method to assay the glycolonitrile-hydrolyzing activity of Rhodococcus sp. CCZU10-1. The preferred carbon and nitrogen sources and ideal inducer were glucose (10 g/L), a composite of peptone (10 g/L) plus yeast extract (5 g/L), and ?-caprolactam (2 mmol/L), respectively. The optimal growth temperature and initial medium pH for Rhodococcus sp. CCZU10-1 glycolonitrile-hydrolyzing activity were 30°C and pH 7.0. Modified ferric hydroxamate spectrophotometry could potentially be employed to assay other carboxylic acids.     

Laboratory-scale production of acetoin plus diacetyl by Enterobacter cloacae ATCC 27613

Conditions for the laboratory-scale production of acetoin plus diacetyl by Enterobacter Cloacae ATCC 27613 were studied. Thirty-five g acetoin plus diacetyl/50 g sucrose were obtained when fermentation was carried out in 2. 5 liter medium containing 12.5 g peptone and 12. 5 g yeast extract, at pH 7.0, in a 5 liter conical flask on a shaker (240rpm) at 28–30°C for 48 hr. Recovery of pure diacetyl was 85% of the total plus diacetyl.     

海洋红酵母Y2发酵产类胡萝卜素条件的研究

目的 对海洋红酵母Y2高产类胡萝卜素的发酵条件进行优化.方法 在摇瓶条件下,研究培养基成分和培养条件对海洋红酵母Y2生长和类胡萝卜素合成的影响,同时进行海洋红酵母Y2发酵过程的动态分析.结果 海洋红酵母Y2优化培养基组合为葡萄糖45 g/L,蔗糖15 g/L,酵母粉5 g/L,蛋白胨2.5 g/L,磷酸二氢钾1 g/L,磷酸二氢钠3 g/L,硫酸镁7.5 g/L,氯化钾3 g/L,氯化钠5 g/L.最适培养参数为:温度20℃,培养基初始pH为5,接种量为10％,250 mL摇瓶装液量为10～50 mL.类胡萝卜素的合成主要集中在对数生长期和稳定期.海洋红酵母Y2最适收获时间为72 h.种龄以36 h为宜.结论 利用优化培养基,在最适条件下培养海洋红酵母Y2,类胡萝卜素产量达到4.97 mg/L,比基础培养基提高了60.32％.     

Optimization of a cultural medium for bacteriocin production by Lactococcus lactis using response surface methodology.

The medium composition for bacteriocin production by Lactococcus lactis ATCC 11454 was optimized using response surface methodology. The selected six factors based on CM medium were sucrose, soybean peptone, yeast extract, KH(2)PO(4), NaCl, and MgSO(4).7H(2)O. Fractional factorial designs (FFD) and the path of steepest ascent were effective in searching for the main factors and approaching the optimum region of the response. By a 2(6-2) FFD, sucrose, soybean peptone, yeast extract, KH(2)PO(4) were found to be significant factors and had positive effects on cell growth, however, only soybean peptone and KH(2)PO(4) were shown to be the two significant factors for bacteriocin production and had negative and positive effects, respectively. The effects of the two main factors on bacteriocin production were further investigated by a central composite design and the optimum composition was found to be 1% sucrose, 0.45% soybean peptone, 1% yeast extract, 2.84% KH(2)PO(4), 0.2% NaCl, and 0.02% MgSO(4) x 7H(2)O. The optimal medium allowed bacteriocin yield to be doubled compared to CM medium.